In general, inkjet printing machines or printers can include one or more print heads that eject drops or jets of liquid ink onto a recording or image-forming surface. An aqueous inkjet printer employs water-based or solvent-based inks in which pigments or other colorants are suspended or in solution. Once the aqueous ink is ejected onto an image-receiving surface by a print head, the water or solvent is evaporated to stabilize the ink image on the image-receiving surface.
In most aqueous inkjet printers, varying sheet sizes can be employed while printing jobs. The maximum print zone for conventional aqueous inkjet printers is generally a result of the maximum width of a paper path or the maximum width of the print head array. When a customer prints a legal size documents having a long edge feed, with a relatively full image, all jets on the print heads will be consumed. If a customer, however, uses a smaller size or a short edge feed, one or more jets may not see any ink movement for a particularly long period, dependent on the length of the job being printed. As a result, these jets can develop viscous fluid that blocks the jets, causing missing jets if the next job requires these particular jets. To mitigate these problems, a customer or a user will need to run a print head maintenance operation to purge ink from the heads—which is a waste of consumables as well as a productivity hit.